[Bug libstdc++/65756] undefined reference to __atomic_store for odd-sized std::atomic

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65756

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
You need to link to libatomic for objects with sizes that aren't supported
natively by the CPU.